Esters of sulphato-carboxylic acids



Patented June 21, 1938 James Herbert Werntz, Wilmington, Del assignor toE. I. du Pont de Nemours it Comlmingto na mwi ware 11, Del.,a-corporation of Dela- No Drawing. Application June 10, 192.7, SerialNo. 147,486

17 Claims.

This invention relates to new chemical compounds, their methods ofproduction and their technical uses. and more particularly to the.

manufacture-and utilization of secondary straight chain alkyl esters ofmono-sulphato-polycarboxylic acids wherein the alkyl groups contain 6 ormore carbon atoms and the sulphato-polycarboxylic acids contain lessthan 15' carbon atoms and have no hydroxyl substituents.

10 This application is a continuation-in-part of my co-pendingapplication, Serial Number 757,- 465, filed December 14, 1934, whichbecame U. S. Patent No. 2,104,782 on January 11, 1938.

. This invention has as an objectthe preparation of a number of newchemical compounds which have surface active properties. A furtherobject is to manufacture these new chemical compounds by novel andeasily conducted processes from relatively inexpensive raw materials. Astill further object is to apply these new compounds in variousconnections wherein surface active compounds are commonly employed.Other objects will appear hereinafter.

These objects are accomplished by the following invention which relatesgenerally to the production of secondary straight chain dialkyl estersof aliphatic mono-sulphato-dicarboxylic acids wherein the alkyl groupscontain 6 or more carbon atoms and the sulphato-dicarboxylic acidscontain less than 15 carbon-atoms and have no hydroxyl substituents. Inthe preferred em- .s bodiment these objects are accomplished by theproduction of esters oi aliphatic mono-sulphatodicarboxylic acids havingfrom 3 to 6 carbon atoms and having no hydroxyl substituents withsecondary straight chain aliphatic alcohols having 6 or more carbonatoms.

The following examples will serve to illustrate this invention.

Example 1 Sodium dKOCtl/l-Z) .iulphato-succinateL-l'ly parts by weightof di(octyl-2) malate, which boiled at 170-173 C. at 3 mm., wasdissolved 46 in 72 parts by weight of anhydrous ethyl ether, and thesolution placed in a reaction vessel equipped with anagitator,thermometer and I (c1. zoo-99.12)

sodium sulphate, filtered, and the ether evaporated at room temperature.19 parts by weight of a light colored, syrupy, product was obtainedafter drying over phosphorus pentoxide in a vacuum desiccator. Thesodium di(octyl-2) sul- 5 phato-succinate analyzed 6.4% sulphurindicating a purity greater than 92%. Thisproduct was found to be a veryefiicient wetting agent for cotton yarn.

Example 2 10 Sodium di(octyl-3) sulphat0-succmate.-17.9 parts byweight'of di(octy1-3) malate was dissolved in '72 parts by weight ofanhydrous ethyl ether and sulphated with 6.4 parts by weight ofchlorosulphonic acid under the conditions described in the. precedingexample for the preparation of sodium di(octyl-2) sulphato-succinate. 23parts by weight of sulphated ester were ob tained which analyzed 6.4%sulphur and indicated a purity greater than 91%. This'product is anefiicient wetting agent for cotton textiles.

The di(octyl-=3) malate was prepared by esteritying octanol '3 withmalic acid using a catalytic amount of paratoluene sulphonic acid andethylene dichloride as the solvent for removing the 25 water liberatedduring the course of the reaction. The product was purified by washingthe ethylene dichloride solution with water and distilling oil? theethylene dichloride. The product was a water-white oil, and wastherefore not distilled prior to the sulphation.

Example 3 Sodium di(he:cyl-3) sulphato-succinate.15.l parts by weight ofdi(hexyl-3) malate, which 35 distilled at 150-155 C. at 2 mm., wasdissolved in 36 parts by weight of anhydrous ethyl ether, and thesolution placed in a reaction vessel equippedwith an agitator, droppingfunnel, and thermometer. A solution of 5.84 parts by weight ofchlorosulphonic acid was prepared by dissolving the acid in 36 parts. byweight of anhydrous ethyl ether, and the acid solution allowed to dropslowly into the solution of the ester. After addition 01' the acid, thesolution was stirred for an additional 2 hours at about 0 C. It was thenpoured into 200 grams of ice and neutralized with a 4% aqueous sodiumhydroxide solution. The sulphated ester was only-sparingly soluble inethyl ether, so the ether layer was removed 5 and the sulphated ester inthe aqueous solution evaluated as awetting agent. It displayed wettingproperties for cotton textiles but in this respect was inferior tosodium di(octyl-3) sulphato-succinate.

' straight chain aliphatic alcohols which are useful in this connectionare the various isomeric normal secondary hexanols, heptanols, octanols,nonanols, decanols, undecanols, dodecanols, tridecanols, -tetradecanola,pentadecanols, hexane-- canols, heptadecanols, and octadecanols,specific examples of which are hexanol-3, ,heptanol-Z.

octanol-2, octanoL-S, nonanol-ii, nonanol-4. nonanol-5, decanol-5,undecanol-Ii, undecanol-G, tridecanol-7, pentadecanol-B, heptadecanol-4, etc. In the preparation of wetting agents for cotton textiles, itispreferred to prepare the esters which are to be sulphated from straightchain secondary alcohols containing from 6 to 10 carbon atoms. Startingout in this manner, there may be obtained secondary straight chaindialkyl esters of sulphatosuccinic acid wherein the alkyl groups containfrom 6 to 10 carbon atoms. In place of individual alcohols, mixturesthereof may be used, the various components of which may vary fromtraces to major fractions.

While the esters which are to be sulphated may be made from anymonohydroxy polycarboxylic acid which contains less than 15 carbonatoms,'lt is preferred to use acids having from 3 to 8 carbon atoms.Aromatic acids, such as 3- hydroxy crthophthalic and 4-hydroxyorthophthalic, and tricarboxylic acids, such as citric, may be used inthis connection, but generally they are not to be preferred; Forinstance, a di(octyl-2) hydroxy phthalate-may be prepared from one ofthe hydroxy phthalic acids and con- I vertedwith chlorosulphonic acid toa di(octyl-2) sulphato-phthalate. It is generally preferred, however, tomake the esters which are to be sulphated from aliphatic monohydroxydicar-z boxylic acids containing from 3 to 6 carbon atoms such astartronic, malic, methyl tartronic, ethyl tartronic, beta-methylmalic,alpha-hydroxy glutaric, beta-hydroxy glutaric, alpha-hydroxy adipic,beta-beta-dimethyl malic, beta-ethyl malic, etc. At present I prefer touse malic acid for preparing the esters to be sulphated above any of theother acids mentioned'in this paragraph.

Esters which are to be sulphated may be prepared by any method known tothe art, e. g., by reacting the alcohol or the alkali metal alcoholatewith the acid, acid chloride, or acid anhydride, or by esterinterchange. Usually the esters to be sulphated are prepared bycsterifying all'of the carboxyl groups of the particular polycarboxylicacid employed with a secondary straight chain aliphatic alcoholcontaining 6 or more carbon atoms. Esters which are to be sulphated mayalso be made in which only one of the carboxyl groups is esterified witha secondary straight chain alcohoLhaving 6 or more carthe same secondaryalcohol.

bon atoms. Each of the carboxyl groups of a dicarboxylic acid may beesterifled with the same or with different alcohols. In the case of theesters employed for making the products described in the above examples,both of the carboxyl groups of the acid have been esterified with Estersto be sulphated may also be obtained by esterifying one 7 carboxyl groupof a dicarbom'iic acid with a normal secondary alcohol containing 6 ormore carbon atoms and the other carboxyl group with a dissimilar alcoholsuch as ethanol, butanol, cyclohexanol, normal octanol,2-ethylhexano1-l, 4-methyl hexanol-l, etc. I at present prefer toprepare the esters which are to be sulphated by esterifying both of thecarboxyl groups of a monohydroxy dicarboxylic acid containing from 3 to6 carbon atoms-especially malic acid with a secondary straight chainaliphatic alcohol containingfi or more carbon atoms.

Estersprepared as indicated in the preceding paragraph or by any othersuitable method may be sulphated by means of such sulphating agents asconcentrated sulphuric acid, oleum, chlorosulphonic acid, pyridinesulphuric acid, etc.

Sulphation may be carried out in the presence of solvents or'diluents,such as water, aliphatic-hydrocarbons, ethyl ether, carbontetrachloride, nitrobenzene, trichloroethylene, symmetricaldichloro-ethyl ether, etc. Sulphation is advisably carried out withinthe temperature range of from -20 C. to 35 C. in order to avoid-theformation of sulphonic acids. As indicated by the above examples, it ispreferred to carry out the sulphation in dry ether solution by means oIchlorosulphonic acid at a temperature of about 0 C.

Sulphated'esters produced in accordance with the foregoing directionsare usually neutralized with salt-forming compounds or bases, which maybe inorganic or organic. .All of the free acid groups present in themolecule may be reacted with such bases, although it is contemplatedthat products containing a'free sulphate or carboxyl group may beproduced and utilized. It is generally preferred to neutralize thesulphated esters with an alkali metal hydroxide, such as sodiumhydroxide, in order to obtain their alkali metal salts. I may also useinorganic bases such as 'soda ash, ammonium hydroxide, potassium hy-,droxide', lithium hydroxide, magnesium hydroxide, calcium hydroxide,and barium hydroxide for neutralizing the sulphated esters. Amines suchas aniline, toluidine, cyclohexyl amine, pyridine, piperidine, dim'ethylamine, ethyl amine, di-

The new compositions covered in this case belong to the class of surfaceactive or capillary active materials in that they have colloidalproperties and may, therefore, be advantageously used in any '.processinvolving wetting, penetrating, deterging, dispersing, emulsifying,frothing, foaming and kindred phenomena. These compositions may beemployed in pure or standardized "form, and, if desired, in conjunctionwith mown processing or treating agents. They may be used by themselvesor in combination with other surface active agents in any relation inwhich surface active agents having colloidal properties have heretoforebeen used.

Many uses of these new compositions are connected with treatments forprocessing and improving natural and synthetic textile materials.

45 ethanol amine, butyl amine, triethanol amine,

A few representative uses of these new products as textile assistantswill be mentioned in order' I g for cleansing and scouring vegetable andanimal sulphate or calcium chloride,

fibers when removing fatty or oily materials. When added to flax rettingbaths, they function as wettingand penetrating agents. They may beemployed as assistants in .fulling and felting processes. They may beused in sizing preparations in combination with the usual materials.

such as starches or gelatine or their equivalents, clays, talcs,weighting salts such as magnesium oils and oils processed by oxidation,polymerization, sulphonation, etc. The penetrating power of these newcompositions is utilized with advantage when they are added to bathscontaining starch ferments which are employed for removing sizing fromtextile materials. These products function as useful wetting, cleansing,and penetrating agents in bleaching liquors such as those used in thekier boiling of cotton goods. They may be added to the lye liquors usedfor mercerizing cotton goods. They improve" the absorption capability'of fibrous materials when such materials are subjected to treatmentsfor finishing,

. beused alone or in combination with other materials for lustering ordelustering fabrics. They may be employed to oil or lubricate textilematerials and as' assistant's in processes of weighting' or loadingfabrics. They may be used as assistants in silk .degumming liquors andsilk soaking solutions. I

Another important class of uses of these new composit ons is asassistants in the preparation and application of dyestuffs. Th'ey may beused in the preparation of dyestuffs in readily dis- 'persible form andfor the production of inorganic pigments-or pigments of azo, basic,acid,

vat, and sulphur dyes in a finely divided con ,dition. As penetrants-and wetting agents they are useful in softening andtreating baths forhides' and skins, particularly in baths used for fat-liquoring leather.pounds are useful for pretreating leather prior to dyeing.

, The dispersing and emulsifying powers of these new-compositions giverise to many. interesting uses. They may be utilized for convertingliquid or solid substances normallyinsoluble in water, such ashydrocarbons, higher alcohols,

' pitches, and pitchy substances into clear solutions orstable-emulsions or dispersions. They are useful in preparing emulsionsof wax and wax-like compositions which are used as leather dressings orfioor polishes. They may be used to prepare artificial dispersions ofcrude, vulcanized. or reclaimed rubber. They may be used as emulsifiersSolutions of these comin the manufacture of cosmetic preparations suchas'cold creams and lip sticks. They maybe employedfor preparingemulsions of the waterin-oil type such as emulsions of water in suchorganic solvents as are used in the dry cleaning industry.

These compositions may also be used alone as contact insecticides andfor enhancing the spreading and penetrating power of otherparasiticides. They may be employed in agricultural sprays incombination with the ordinary insecticides and fungicides. They areuseful for promating the penetrating power of wood preservatives.

In the paper industry these products may be used as penetrants intheliquors used-for cooking rags and pulp, and. as assistants in papersoftening, filling, and processes to increase absorbency.

These compositions may be employed as detergents in several differentrelations. They may be used in the washing of fruits and vegetables forspray residue removal. They may be used in combination with metalcleaning compounds in neutral, slightly acid, or slightly alkalineliquors. They may be used for paint, varnish, and lacquer cleaners. Theymay advantageously be employed as cleansing'agents in hard water andwhere a fatty or oily film resists the ordinary cleansing media. Theymay be added to soap in hard water baths, since these compositions donot form precipitates so readily in hard waters as soaps and Turkey redoils.

These compositions may be used as aids in various chemical reactions.They may be used to control particle size and shape during precipitationor crystallization of compounds from reaction mixtures. They may be usedto decrease the particle size of insoluble amine hydrochlorides justbefore these amines are to be diazotized.

These compositions also have several miscellaneous uses. They may beemployed as foam stabilizing agents, .especially for use in air-foamfire extinguishing compositions. They may be used to stabilize rubberlatex. They may also be used as frothing and collecting agents in oreflotation processes, and in other processes such as the recovery offixed oil from the oil sands. These compounds may be used in toothpaste,nonspattering margarins and may be employed-es emulsifying agents forsynthetic rubber latex such as neoprene.

The above description and examples are intended to be illustrative onlyand not to limit the scope of the invention. Any departure therefromwhich conforms to the spirit of the invention is intended to be includedwithin the scope of the appended claims.

I claim: 1 1. A secondary ester of a mono-sulphato-polycarboxylic acidwherein the alkyl group contains at least 6 carbon atoms and thesulphato-polycarboxylic acid contains less than 15 carbon atoms and hasno hydroxyl substituents.

2. A secondarystraight chain dialkyl ester of an aliphaticmono-sulphato-dicarboxylic acid' phato-dicarboxylic acid whergn thealkyl groups contain at least 6 carbon atomsand the sulphatestraightchain neutral alkyl dicarboxylic acid contains from 3 to 6 carbon atomsand has no hydroxyl substituents.

4. A process of making the products defined in claim 3 which comprisessulphating a secondary straight chain dialkyl ester of an aliphaticmonohydroxy dicarboxylic acid wherein the alkyl groups contain at least6 carbon atoms and the dicarboxylic acid contains from 3 to -6 carbonatoms, and neutralizing the sulphated ester with an alkali metalhydroxide.

5. A secondary straight chain dialkyl esterof sulphato-succinic acidwherein the alkyl groups contain at least 6 carbon atoms.

6. An alkali metal salt of a secondary straight chain dialkyl ester ofsulphato-succinic acid wherein the alkyl groups contain at least 6carbon atoms.

7. A process of making the products defined in claim 6 which comprisessulphating a secondary straight chain dialkyl ester of malic acidwherein the alkyl groups contain at least 6 carbon atoms, andneutralizing the sulphated malate ester with an alkali metal hydroxide.

8. A secondary straight chain dialkyl ester of sulphato-succinic acidwherein the alkyl groups contain from 6 to 10 carbon atoms.

9. An alkali metal salt of a secondary straight chain dialkyl ester orsulphato-succinic acid wherein the alkyl groups contain from 6 to 10carbon atoms.

10. A process of making the products defined in claim 9 which comprisessulphating a secondary straight chain dialkyl ester of malic acidwherein the alkyl groups contain from 6 to 10 carbon atoms by reactingan ether solution of said ester with chlorosulphonic acid, andneutralizing the sulphated ester with an aqueous solution of an alkalimetal hydroxide.

11. A di(octyl-3) sulphato-succinate.

12. Sodium di(octyl-3) sulphato-succinate.

13. A process of making sodium di(octyl-3) sulphato succinate whichcomprises adding chlorosulphonic acid to a dry ether solution ofdi(octyl-3) malate, stirring the reaction mixture, and neutralizing thesulphated malate ester with an aqueous solution of sodium hydroxide.

14. A di(octyl-2) sulphato-succinate.

15. Sodium di(octyl-2) suiphato-succinate.

16. A di(hexyl-3) sulphato-succinate.

17. Sodium di(hexyl-3) sulphato-succinate.

J AMIES HERBERT WERNTZ.

